A better-resourced and coordinated search and rescue effort may have saved more lives after the collapse of a building following the 2011 Christchurch earthquake, according to a New Zealand coronial report.

Coroner Gordon Matenga has been inquiring into the deaths of eight people who survived the collapse of the CTV building but died before rescuers could reach them.

Some of those trapped sent text messages and made urgent phone calls for help.

While praising the rescue effort, Mr Matenga said: "More people, more resources, better communication and a better structure … may have improved the chances of saving more lives."

But he said he was not satisfied that such changes would have ensured the survival of the eight victims who were the subjects of his inquiry.

He officially ruled that the search and rescue efforts did not contribute to the cause of their deaths.

Adelaide woman Marlene Sumalpong's daughter, Rhea Mae, was among eight English-language students who survived for hours after the building collapsed but died before they could be saved.

Ms Sumalpong said the report's findings are of no comfort.

"I want to have justice for my daughter," she said.

Police are still investigating whether anyone can be charged over the collapse.